AMR transmitter and method using multiple radio messages

ABSTRACT

The invention provides a method and several types of devices for converting meter reading signals into data messages including a first message ( 40 ) having meter data ( 44 ) representing consumption of a utility, and meter diagnostic status data ( 43 ), and a second message ( 60 ) having meter reverse flow data ( 63 - 65 ) and meter diagnostic data ( 66 ) particular to an electronic flow meter, and receiving, said first message ( 40 ) and said second message ( 60 ) and converting first message and said second message to radio frequency signals ( 25 ) and transmitting said radio frequency signals ( 25 ) to a receiver ( 22, 24 ).

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation, and claims the benefit of U.S.application Ser. No. 12/489,530, filed Jun. 23, 2009, the entirety ofwhich is hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to automatic meter reading (AMR) systemsthat include an electronic meter or meter register and a network forcollecting utility metering data.

DESCRIPTION OF THE BACKGROUND ART

Recently, electronic meter registers have begun to appear in utilitymetering applications. An example of a separate electronic meterregister is disclosed in Olson, U.S. Pat. No. 6,611,769. An example ofan electronic meter register integrated in one housing with a mechanicalmeter is disclosed in Lazar et al., U.S. Pat. No. 7,412,882.

Traditionally, ultrasonic and acoustic type meters have been used formeasuring industrial and wastewater flows. Examples of such meters aredisclosed in Lee, U.S. Pat. No. 3,935,735; Lee. et al., U.S. Pat. No.4,052,896 and Vander Heyden et al., U.S. Pat. No. 4,633,713. Such metersdepend on signals impinging upon particles in the flow stream, Dopplermethods and time-of-travel characteristics to measure the flow. EuropeanPatent Publication 1493998A2, published Jun. 8, 2004, discloses anultrasonic flow meter for utility usage.

The use of some types of electronic meters, such as ultrasonic types,fluidic oscillatory types and electromagnetic sensing meters, has beenlimited due to elements of cost. With advance in the design andconstruction of these devices, it may now be possible to meetmarketplace pricing constraints.

Electronic meters have not previously been in widespread use in utilityapplications in the United States due to cost factors. As raw materialcosts and manufacturing costs are rapidly increasing at this time, thereis a now a cost advantage to converting mechanical-based meteringsystems to electronic metering systems. Also, electronic meters arewell-suited for use in AMR systems. Electronic meters provide greateraccuracy than some other types of known utility meters. And, electronicmeters are well adapted to flows with particles included.

Electronic meters and meter registers may be able to handle certain datathat is particular to electronic meters such reverse flow data, emptypipe data and end-of-life data. This, however, requires improvements innetwork communication protocols to handle the additional data.

SUMMARY OF THE INVENTION

In one aspect, the invention relates to a method and circuitry forcommunicating metering data in a pair of related messages to a receiver.The first of two messages includes a transmitter ID number, utilityconsumption data, and diagnostic, data for conventional conditions suchas, for example, a tamper indication, a leakage indication, and a stuckmeter indication. A second message is provided to add reverse flow dataand diagnostic data, particular to an electronic meter, such as an emptypipe indication, and an end of life indication.

In a further aspect of the invention, status data are added to the firstmessage to indicate the presence of reverse flow data and diagnosticdata, such as empty pipe, low temperature and end-of-life in the secondmessage.

In a further aspect of this invention, the second message can betransmitted less frequently than the first message by an order ofmagnitude, or the interval can be extended for the purpose of conservingthe life of one or more batteries.

The invention also provides diagnostic data and profiling data forreverse flow conditions over the last seven days and the lasttwenty-four (24) hours.

The invention is provided in three physical embodiments, one embodimentwhich fully integrates a meter, a meter register and a radio transmitterin one housing, and two other embodiments in which meter data is outputthrough a data port from the meter register to a separate transmitterassembly, which can be mounted to a pit lid.

Other objects and advantages of the invention, besides those discussedabove, will be apparent to those of ordinary skill in the art from thedescription of the preferred embodiments which follows. In thedescription, reference is made to the accompanying drawings, which forma part hereof, and which illustrate examples of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an AMR system, illustrating a mobilereceiver in a drive-by vehicle and a fixed receiver for receivingtransmissions from a transmitter associated with a utility meter;

FIG. 2 is a side view in elevation of a meter assembly and a separatetransmitter assembly installed in a subsurface pit enclosure;

FIG. 3 is a side view in elevation of an integrated meter, metertransducer and transmitter assembly installed in a subsurface pitenclosure;

FIG. 4 is a side view in elevation of a conventional water meter with ameter register and a transmitter assembly of the present, inventioninstalled in a subsurface pit enclosure;

FIG. 5 is a sectional view of the meter assembly of the presentinvention of FIG. 2;

FIG. 6 is an end view of the meter assembly of FIG. 2 with parts of thehousing broken away for a view of the interior;

FIG. 7 is a block diagram of a signal processing section within themeter of the present invention of FIG. 4;

FIGS. 8-9 are data maps of a first message transmitted by thetransmitter portion of FIGS. 2-4 to a receiver; and

FIGS. 10-11 are data maps of a second message transmitted by thetransmitter portion of FIGS. 2-4 to a receiver.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 and 2, in this example, the invention isincorporated in a water meter assembly 16, 20, and a radio transmitterassembly 10 disposed in a subsurface pit enclosure 11 and connected by acable 21. The pit enclosure 11 is typically made of metal, concrete,plastic or other materials with a lid 15 which is removable to open theenclosure 11 for access. The pit enclosure 11 is located along the routeof water supply pipe 17. The housing assembly 16, 20 includes a lower,tubular housing 16 for housing the water metering elements and forwithstanding water pressure, which is connected in the water supply line17 by coupling nuts 18 and 19 (FIG. 2). An upper housing 20 for a watermeter register, and in some other embodiments, a transmitter, ispositioned on top of the lower housing 16. This upper housing 20 ispreferably made of plastic, such as polystryrene, ASA Luran or anequivalent non-metallic material. A visual display of a types known inthe art would be seen from the top of the upper housing 20. In recentyears, the meter register has included a transducer for converting: i)mechanical movements, ii) movements of a magnet or iii) electrical metersignals to electrical signals of a type known in the art for signalingunits of consumption of a utility.

As further seen in FIGS. 2 and 4, in a “remote version” of the present,invention, a shielded cable 21 connects the electronics in the meterregister housing 20, 20″ to a transmitter assembly 10, 10″, which ishoused in a tubular transmitter housing 28, 28″, preferably of a plasticmaterial, such as polystryrene, ASA Luran or an equivalent non-metallicmaterial. The transmitter housing 28, 28″ hangs down from the pit lid 15and includes its own battery, as is known in the art. The transducerelectronics in the meter register housing 20, 20″ transmits electricalsignals representing units of consumption of a utility to thetransmitter assembly 10, 10″, which incorporates meter data and otherdata in messages encoded for transmission through a radio network.

FIG. 2 provides a version in which the meter and meter-register areintegrated, but where the transmitter assembly 10 is contained in aseparate housing. FIG. 4 represents the traditional configuration of aseparate meter register 20″ mounted on a water meter housing 16″ with aseparate transmitter assembly 10″.

In a fully “integrated version” of the invention seen in FIG. 3, ahousing 20′ encloses both meter register and transmitter formed on acircuit board 26 and an antenna 29 for transmitting signals directlythrough the pit lid 15 to a radio signal receiver 24. In this version,the pit lid 15 is made of a non-RF-interference material, for example,plastic, concrete or other materials that will not significantly changethe direction of, or attenuate, RF signals.

The transmitter assemblies 10, 10″, 26 communicate via RF signals with areceiver 24 which can be a mobile receiver in a vehicle 27 seen inFIG. 1. The transmitter assemblies 10, 10″ 26 each transmit radiofrequency signals encoded with messages and meter data, as will befurther described below in relation to FIGS. 8-11. The meter data iscollected from various customer locations and transmitted to a centraloffice for processing for billing purposes.

In the present invention, the transmitter assemblies 10, 10″, 26 alsocommunicate, via RF signals with a fixed receiver 22 installed on autility pole 23 seen in FIG. 1, within a range of up to one thousandfeet of the transmitter unit 10. The transmitter assembly 10, 10″, 26transmits electronic messages, including meter data, as will be furtherdescribed below in relation to FIGS. 8-11.

Referring to FIG. 5, in the integrated meter, meter register andtransmitter (FIG. 3 version), the meter housing 16 is made of brass oranother suitable material, preferably lead-free, to withstand waterpressures. Inside the housing 16 is a plastic metering insert 38positioned in the conduit 16 and supporting two mirrors 32, 33 at minusforty-five degrees and plus forty-five degrees, respectively, relativeto vertical. The assembly also includes two ultrasonic transducers 30,31, a temperature sensor 39, a signal processing section, 50, and one ormore batteries 37. A first ultrasonic signal will be transmitted throughone of the transducers 30 downward, to reflect off one of the mirrors 32at ninety degrees, to travel through the flow stream 35 as an ultrasonicsignal parallel to the flow stream and the meter housing 16, which isshaped like a pipe. The signal will then reflect off the second mirror33 at ninety degrees and be detected by the second ultrasonic transducer31 and converted to an input to the signal processing section 50 in FIG.7. A second signal is then transmitted in a reverse direction throughsecond one of the transducers 31, downward to reflect off the second oneof the mirrors 33 at ninety degrees to travel through the flow stream 35opposite the direction of flow 35 and parallel to the direction of flowand the conduit 16. The signal will then reflect off the first-mentionedmirror 32 at ninety degrees and be detected by the first ultrasonictransducer 30 and input to the signal processing section 50 in FIG. 7. Atemperature sensor 39 is also positioned with one end projecting intothe flow stream 35.

Referring to FIG. 7, the housing 20′ in FIGS. 3 and 5, encloses anelectrical signal processing section 50 typically formed on a circuitboard 26 and including a microelectronic CPU 51 operating according to acontrol program, of program instructions stored in a program memory 52,which may be internal to the CPU 51. The memory 52 is flash memory thatcan be altered with a special programming unit, which communicates withthe transmitter through an optical I/O data port 56, preferablyutilizing the IrDa (infrared frequency) protocol. Data profiling datafor reverse flow is read through this optical I/O data port 56 as well.This can be stored in a non-volatile memory external to the CPU 51.

As further seen in FIG. 7, the CPU 51 receives signals from anultrasonic transducer interface 53. This section 53 can receive theultrasonic signals 34 after conversion by the transducers 30, 31, toeventually produce data signals at a logic level of power, such as 3.6dc volts, for digital circuitry. The CPU 51 produces metering data inmessages, which are converted to radio frequency (RF) signals by an RFtransmitter section 54 that modulates signals for transmission. Thesesignals can then be signaled directly through an antenna 29 (FIGS. 6 and7) to an RF receiver, represented generally by block 24 in FIG. 3,provided that the pit lid 15 is not made of metal so as to interferewith the radio frequency signals. The message data contained in the RFtransmissions is mapped in FIGS. 8-11.

In the embodiments in FIGS. 2 and 4, a meter transducer section (notillustrated) in the meter register housing 20, 20″ would transmit datarepresenting units of utility consumption through a cable output portand through the cable 21, to respective transmitter assemblies 10, 10″seen in FIGS. 2 and 4 for conversion to RF signals and transmission to aradio receiver 24 seen in FIG. 1. In these embodiments, the transmitterassemblies 10, 10″ would include a signal processing section of a typeseen in FIG. 7, including a CPU, a program memory, an RF transmittersection and an antenna to convert the meter data to radio frequencysignals according to a message protocol. The information in the radiomessages, as transmitted from the transmitter assemblies 10, 10″, wouldbe organized as illustrated in FIGS. 8-11.

The radio signals can be transmitted from the AMR transmitter in severalmodes of operation, in a one-way AMR network. Although the invention isdisclosed in one example, in a one-way network, the invention could alsobe applied in a two-way communication network, where each radiotransmitter described herein would be included as one portion of atransceiver. Drive-by vehicles 27 (FIG. 1) will be able to read thetransmitter signal and collect meter readings. This type of system usesa battery for power and this mode of transmission provides long batterylife using small batteries. This signal may be read by fixed receivers22 provided they are not too far from the transmitter.

To reach fixed location receivers 22 (FIG. 1), it is desirable toprovide a transmission utilizing a higher power level than the prior artlow power methods used for communicating with drive-by receivers. In thepresent invention, this is accomplished by sending out afrequency-hopping spread-spectrum (FHSS) signal over twenty-fivechannels. Various time periods can be observed in sending out the twomessages, and the second message may be sent out less frequently thanthe first message.

FIGS. 8-11 show the data in the two messages referred to more generallyabove. The messages contain data for implementing various alarmconditions, including a reverse flow alarm, a potential leak alarm, astuck meter condition, (no usage for 30 days), a tamper alarm, an emptypipe alarm, a low temperature alarm and an end-of-life notification. Thereverse flow alarm, the empty pipe condition and the end-of-lifenotification are conditions which are particularly related to electronicflow meters. The low temperature condition is a feature of theultrasonic flow meter that is available, and is sensed with the additionof a temperature sensor 39 to the meter housing assembly 16, 20 as seenin FIG. 4.

As seen in FIG. 8, the first message 40 includes a header 41 offorty-eight (48) bits, a data field and an error code field in the formof 120 bits comprising twenty (20) hexadecimal digits. The first sixhexadecimal digits, D1-D6, provide digits of a transmitteridentification number. The next two hexadecimal digits, D7-D8, providestatus data 43 seen in more detail in FIG. 9. This is followed by sixhexadecimal digits, D9-D14, of meter data representing consumption ofthe utility by the customer. This is followed by two more hexadecimaldigits, D15-D16, providing the most significant digits of a transmitteridentification number. This is followed by four more hexadecimal digits,D17-D20, providing an error checking code, preferably a cyclicredundancy code (CRC).

Referring to FIG. 9, the status byte 43 includes status bits indicatingpresence of alarm data in a following message for the tamper alarm 47,other alarms 48 such as empty pipe, low temperature (3 degrees C. orbelow) or end-of-life, potential leak alarm 49 (no usage 24 hours),reverse flow alarm 57 or stuck meter (no usage) alarm 58. The last threebits 59 indicate a meter encoder type, such as RTR, ADE or gas, whichare types known from the commercial products of the assignee.

As seen in FIG. 10, the second message 60 also includes a header 61 offorty-eight (48) bits, a data field and an error code field in the formof 136 bits comprising thirty-four (20) four-bit hexadecimal digits. Thefirst eight hexadecimal digits, D1-D8, provide four bytes of atransmitter identification number. The next six hexadecimal digits,D9-D14, provide reverse flow data 63. This is followed by fourhexadecimal digits, D15-D18, of “Δ reverse flow” data 64 in the lasttwenty-four (24) hours. This is followed by four more hexadecimaldigits, D19-D22 providing of “Δ reverse flow” data 65 in the last seven(7) days. This is followed by four more four more hexadecimal digits,D23-D26, providing two bytes of status data 66 seen in more detail FIG.11. This is followed by two more hexadecimal digits, D27-D28, providingdata for max flow rate and by four more hexadecimal digits D29-D32 (notshown in FIG. 9) providing an error checking-code, preferably a cyclicredundancy code (CRC).

FIG. 11 shows the details of the two status bytes 66 in which meter sizeis defined by four bits 68, a unit of measure is defined by the nextthree bits 69, units of time are defined by the next two bits 70, andindicators are provided, for the following alarms: tamper 71, leak 72,reverse flow 73, stuck meter 74 (no usage for 30 days), end-of-life 75and low temperature 76.

It should noted that the alarm status bits 47-49 and 57-58 in the firstmessage in FIG. 8 indicate the presence of actual alarm data in thesecond message. It should now be apparent how the first message andsecond message contribute to increasing the diagnostic data available inthe two messages due to the capabilities of an ultrasonic flow meter.This provides advantages in diagnosing operating-conditions, which havenot been known before the invention.

This has been a description of the preferred embodiments, but it will beapparent to those of ordinary skill in the art that variations may bemade in the details of these specific embodiments without departing fromthe scope and spirit of the present invention. For example, although thepreferred embodiment uses ultrasonic signals to develop a meter reading,it will be apparent that the same messaging can be applied to fluidicoscillator type or electromagnetic type meters and that such variationsare intended to be encompassed by the following claims, unlessspecifically excluded.

We claim:
 1. Apparatus for use in transmitting radio messages in anautomatic meter reading network, the apparatus comprising: a processingcircuit for converting meter reading signals into messages, including afirst message having utility consumption data and a meter diagnosticstatus message indicating the presence of alarm data in a second messagegenerated after the first message, the second message having meterreverse flow data and meter diagnostic data including the alarm dataproviding additional information related to the alarm data in the firstmessage; and transmitter circuitry configured for receiving said firstmessage and said second message from the processing circuit, thetransmitter circuitry converting said first message and said secondmessage into radio frequency signals and transmitting said radiofrequency signals to an external receiver.
 2. The apparatus as recitedin claim 1, further comprising an electronic flow meter, the apparatusbeing housed in one housing assembly that can be installed in as pipe.3. The apparatus as recited in claim 2, wherein the electronic flowmeter is more particularly an ultrasonic flow meter, and the assemblyfurther comprises a low temperature sensor disposed in the flow streamand wherein the diagnostic data includes a low temperature event signal.4. The apparatus as recited in claim 1, further comprising an electronicflow meter and wherein the electronic flow meter and the processingcircuit for converting meter reading signals into messages, are housedin a housing assembly that can be installed in a pipe, and wherein thetransmitter circuitry is housed in a separate housing.
 5. The apparatusas recited in claim 4, wherein the electronic flow meter is moreparticularly an ultrasonic flow meter, and the assembly furthercomprises a low temperature sensor disposed in the flow stream andwherein the diagnostic data includes a low temperature event signal. 6.The apparatus of claim 1, wherein the processing circuit and thetransmitter circuitry are enclosed in a transmitter housing separatefrom a meter and a Meter register that provides signals representingunits of utility consumption to the transmitter housing.
 7. Theapparatus as recited in claim 1, wherein the diagnostic data includes atleast one of: reverse flow data, empty pipe data and battery life data.8. The apparatus as recited in claim 1, wherein the diagnostic dataincludes reverse flow indicating reverse flow conditions over a lastseven days and includes data indicating reverse flow conditions over alast twenty-four hours.
 9. The apparatus as recited in claim 1, whereinthe second message is transmitted less frequently than the firstmessage.
 10. The apparatus as recited in claim 1, wherein the firstmessage and the second message are transmitted as frequency-hoppingspread-spectrum signals.
 11. The apparatus as recited in claim 1,wherein the first message and the message are transmitted by circuitrycomprising a single transmitter.
 12. The apparatus as recited in claim1, further comprising an optical data port communicating with circuitryfor converting meter reading signals, the optical data port providingaccess to an external device for reading reverse flow profiling data fora defined time period from the processing circuit.
 13. A method oftransmitting radio frequency signals representing utility metering data,the method comprising: converting meter reading signals from a flowsensing device into messages, said messages including a first messagehaving utility consumption data and a meter diagnostic status messageindicating the presence of alarm data in a second message generatedafter the first message, the second message having meter reverse flowdata and meter diagnostic data including the alarm data providingadditional information related to the alarm data in the first message;and receiving said first message and said second message and convertingfirst message and said second message to radio frequency signals andtransmitting said radio frequency signals to a receiver.
 14. The methodas recited in claim 13, wherein the electronic flow meter is moreparticularly an ultrasonic flow meter and the method further comprisingsensing temperature in the flow stream and wherein the diagnostic dataincludes a low temperature event signal.
 15. The method as recited inclaim 13, wherein the diagnostic data includes at least one of reverseflow data, empty pipe data and battery life data.
 16. The method asrecited in claim 13, wherein the radio signals carrying the secondmessage are transmitted less frequently than the radio signals carryingthe first message to conserve power consumption in the utility meterinterface device.
 17. The method as recited in claim 13, wherein thesecond message is transmitted less frequently than the first message.18. The method as recited in claim 13, wherein the meter reverse flowdata includes data indicating reverse flow conditions over a last sevendays and includes data indicating reverse flow conditions over a lasttwenty-four hours.